[TowerTalk] Remote Tuner with ZS6BKW or OCF Antenna

[Dan Maguire]

In his original post on the subject Phil wrote:
>>> Has anyone experimented with using a remote Tuner (LDG, MFJ, etc.) near the antenna to reduce losses in the coax to the rig?  What would be the results in say, using a remote tuner on a ZS6BKW after the ladder line conversion to a SO239 for coax? ... If a low SWR is obtained at the remote tuner, my thinking is the loss on the coax run to the shack would be very low.

If by "experimented with" you wish to include modeling in addition to "real world build it and test" then EZNEC or the combination of EZNEC and AutoEZ can help.  With EZNEC's "L network" feature you can model a remote auto-tuner (including coil and capacitor losses) and with EZNEC's "lossy transmission line" feature you can include transmission line losses in the model.  Using AutoEZ lets you greatly simplify the steps needed to build the model.

So you could, for example, model one configuration with the tuner located in the shack and another configuration with the tuner at some remote location and then compare total system loss (including tuner loss and transmission line loss) between the two.

For a detailed example of modeling an auto-tuner see the second bullet here:

http://ac6la.com/aetltu.html

Note that the antenna in that example is a simple dipole but the steps needed to model the tuner are the same regardless of the antenna.

For some examples of including transmission line loss in a model see the last three bullets here:

http://ac6la.com/aecollection7.html

Again, let me stress that this is all "modeling" as opposed to "I built exactly what you described and this is my experience."

Dan, AC6LA
http://ac6la.com